Surface-contact electric railway.



No. 860,726.. PATENTED JULY 23, 1907.-

W M. BROWNZ Y SURFACE GONTAGT ELECTRIC RAILWAY,

APILIOATIOF nun JULY 29. 1904.

$ .4 TTORNEY.

TH: ncmus PETERS cm. wast-" 4010". n. c.

UNITED STATES PATENT OFFICE.

WILLIAM MILTON BROWN, OF JOHNSTOWN, PENNSYLVANIA, ASSIGNOR TO THE LORAINSTEEL COMPANY, A CORPORATION OF PENNSYLVANIA.

SURFACE-CONTACT ELECTRIC RAILWAY.

Specification of Letters Patent.

Patented July 23, 1907.

Application filed July 29,1904. Serial No. 218,656.

To all whom it may concern:

Be it known that I, WILLIAM MILTON BROWN, of Johnstown, in the county ofCambria and State of Pennsylvania, have invented a new and usefulImprovement in Surface-Contact Electric Railways, of which the followingis a full, clear, and exact description, reference being had to theaccompanying drawings, which form a part of this specification.

My invention has relation to surface contact electric 1O railways, andis designed to provide means for preventing maintained arcs in thecontact boxes after the passage of a car. These arcs sometimes occur byreason of a heavy surface leakage from the contact box to an adjacenttrack-rail or other conductor, which is sufficient to maintain an arcacross the members of the switch after the latter has opened.

My invention consists in providing means whereby, before the car leavesthe box, any are which tends to hang therein is immediately shortcircuited and extinguished.

The accompanying drawing is a diagrammatic view illustrating myinvention.

A, A, & A designate the-switch devices of three adjacent contact boxesor devices, and a, a, a the surface contact plates thereof.

13, designates the supply conductor or feeder, having branches 1)leading to the boxes.

C designates the usual current collecting skate, shoe, or trolleycarried by the car; D, the car magnets, and

E, the car motor.

R designates a track rail.

F is an auxiliary skate or shoe, placed behind and in line with the shoeD, and electrically connected thereto, or with the circuit thereof, by aconductor such as G.

The purpose of this shoe is to provide means for shortcircuiting any arewhich may form in the boxes, and the operation is as follows-Supposingthe car to be passing in the direction of the large arrow, the shoe 0has left the contact a of the contact device A, and is on 40 the contacta of the box A. If now from any cause, a heavy surface leakage occursfrom the plate a to the rail R, or other adjacent conductors, asillustrated by the chain of small arrows, an arc may tend to bemaintained at S, between the separated contacts of the switch A. Assoon, however, as the auxiliary shoe F contacts with the plate A,another path is established for current to supply this leakage, and thispath being of very slight resistance compared to the resistance of thisarc, it is evident that the current will immediately take the new path,and the arc will be extinguished, being, in effect, completely shortcircuited. When the shoe F leaves the plate a, the circuit is simplybroken at the surface of said plate. The are, being once broken, willnot reform until another car passes. Any suitable indicating device maybe placed in the conductor G, for the purpose of locating the boxeswhere leakage occurs.

It is usual to make the car magnets somewhat longer than the collectingskate or shoe G in order to hold the switching devices of the boxesclosed until the shoe ceases to take current from the box. The auxiliary-skate or shoe should, therefore, be placed sufiiciently behind the carmagnets so that the latter will cease to hold the switch closed beforethe auxiliary shoe makes contact with the plate. Said auxiliary skateis, as shown, also separated from the main skate or shoe by a sufficientspace so that there is a time interval at each surface contact duringwhich neither shoe is in engagement with the said contact. In thismanner, no current is passing through the contacts at the time themagnet ceases to act thereon. V 1

My invention is obviously applicable to various forms of surface contactsystems, and is susceptible of various modifications, without departingfrom the spirit and scope of my invention I do not therefore limitmyself to the particular embodiment which I have herein shown anddescribed.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent is:

In a surface contact electric railway system, the combi- 8O nation withcontact boxes provided each with a movable circuit-closing membertherein, and with a surface portion or cover, a car magnet for acthatingthe circuit closing members, and a current-collecting shoe arranged tocontact with the surface portions or covers of the boxes, and to receivecurrent therefrom, of means for short-circuiting arcs which may hang inthe boxes after the passage of the magnet and shoe, said meansconsisting of a shorter auxiliary shoe in rear of the main collectingshoe, and an electrical connection from the auxiliary shoe to the mainshoe, the auxiliary shoe being spaced from the main shoe and also fromthe magnet to provide a time interval at each contact, after the carmagnet has ceased to act, when the contact is not engaged by eithershoe;substantially as described.

In testimony whereof, I have afiixed my signature in presence of twowitnesses.

IVILLIAM MILTON BRO\VN.

Witnesses E. ii: Cmsswnnn, MAn'rIx ALDl-ZRWICK.

